The present disclosure relates to a sole structure for shoes and a shoe including such a sole structure.
A sole structure has been generally widely known, which includes, as major components, a midsole made of a soft elastic material and an outsole bonded to the lower surface of the midsole. As such a sole structure, for example, Japanese Unexamined Patent Publication No. 2000-333707 proposes a sole structure for athletic shoes. As a sole structure which exhibits enhanced flexibility when touching the ground, for example, Japanese Unexamined Patent Publication No. 2007-508055 proposes a sole structure for athletic shoes.
The sole structure disclosed in Japanese Unexamined Patent Publication No. 2000-333707 includes an outsole having a ground surface on its lower surface, and a midsole made of an elastic material and overlaid above the outsole. The midsole includes a medial-side midsole portion which is arranged at a position corresponding to a medial side of a hindfoot of a foot and extends in a longitudinal direction, and a lateral-side midsole portion which is arranged at a position corresponding to a lateral side of the hindfoot and extends in the longitudinal direction. The lateral-side midsole portion faces, and is spaced apart from, the medial-side midsole portion in a foot width direction.
The sole structure disclosed in Japanese Unexamined Patent Publication No. 2007-508055 has a plurality of grooves (i.e., sipes) recessed upward with respect to the ground surface of the outsole and linearly extending in a foot width direction. These grooves for flexibility are arranged over an area corresponding to an area from the forefoot to the hindfoot of a foot and spaced apart from one another in the longitudinal direction.